.

bigfile/_file_zodb.pyx

@@ -73,6 +73,10 @@ cdef public class _ZBigFile(BigFile) [object _ZBigFile, type _ZBigFile_Type]:
     def loadblk(self, blk, buf):    return self.zself.loadblk(blk, buf)
     def storeblk(self, blk, buf):   return self.zself.storeblk(blk, buf)
 
+    # blkmmapper is pycapsule with virtmem mmapper for the file.
+    # it relies on .wfileh being initialized by .fileh_open()
+    blkmmapper = PyCapsule_New(<void*>&ZBigFile_mmap_ops, "bigfile.blkmmaper", NULL)
+
     # fileh_open wraps BigFile.fileh_open and makes sure that WCFS file handle
     # corresponding to ZBigFile is opened if use_wcfs=True.
     def fileh_open(_ZBigFile zf, bint use_wcfs):
@@ -93,7 +97,9 @@ cdef public class _ZBigFile(BigFile) [object _ZBigFile, type _ZBigFile_Type]:
 
         return super(_ZBigFile, zf).fileh_open(mmap_overlay)
 
-    # blkmmapper returns pycapsule with virtmem mmapper for the file.
+    """
+    # blkmmapper is pycapsule with virtmem mmapper for the file.
+    # it relies on .wfileh being initialized by .fileh_open()
     @staticmethod
     def blkmmapper():
 #    def blkmmapper(_ZBigFile zf):
@@ -118,6 +124,7 @@ cdef public class _ZBigFile(BigFile) [object _ZBigFile, type _ZBigFile_Type]:
         # the capsule is not bound to particular _ZBigFile object because
         # .mmap_* methods receive BigFile* argument which they upcast to _ZBigFile.
         return _ZBigFile_mmap_pycapsule
+    """
 
 
 # _ZBigFile_mmap_pycapsule is pycapsule with functions that we give to
@@ -131,8 +138,8 @@ cdef extern from * nogil:
     """
     const bigfile_ops ZBigFile_mmap_ops
 from cpython cimport PyCapsule_New
-cdef object _ZBigFile_mmap_pycapsule = PyCapsule_New(
-        <void*>&ZBigFile_mmap_ops, "bigfile.blkmmaper", NULL)
+#cdef object _ZBigFile_mmap_pycapsule = PyCapsule_New(
+#        <void*>&ZBigFile_mmap_ops, "bigfile.blkmmaper", NULL)
 
 
 # pywconnOf establishes and returns (py) wcfs.Conn associated with zconn.